Process for preparing brominated phthalimides

Abstract

A process for the preparation of brominated phthalimides that involves mixing tetrabromophthalic anhydride, an organic acid, and an organic dispersing agent in water at approximately 110° C. under 1 bar pressure is disclosed. An amine is added and the reaction mixture is stirred for six hours under approximately 5 bar pressure and heated at least to 120° C. The reactant mass is washed in water and then methanol. The process decreases production time, increases whiteness and purity, and decreases yellowness and particle size of the resulting product.

What is claimed is: 
     
       1. A process for the preparation of brominated phthalimides comprising the steps of reacting tetrabromophthalic anhydride, an organic acid, an acidic dispersing agent, and an amine in water for a sufficient time to form said brominated phthalimides. 
     
     
       2. The process of claim 1, wherein said acidic dispersing agent is an anionic dispersing agent. 
     
     
       3. The process of claim 1, wherein said acidic dispersing agent is selected from the group consisting of benzene, 1,1'-oxybis-; tetrapropylene derivatives, sulfonated, sodium salts; poly(oxy-1,2-ethanediyl),alpha-(nonylphenyl)-omega-hydroxy-, branched phosphates; and poly(oxy-1,2-ethanediyl),-alpha-(dinonylphenyl)-omega-hydroxy-, phosphates. 
     
     
       4. The process of claim 1, wherein the molar ratio of anhydride/amine is approximately 2:1. 
     
     
       5. The process of claim 1, wherein the reaction is carried out under pressure at a temperature of at least 120° C. 
     
     
       6. The process of claim 1, wherein the reaction is carried out under pressure at a temperature between approximately 150°-170° C. 
     
     
       7. The process of claim 1, wherein said organic acid is selected from the group consisting of formic acid, acetic acid, and propionic acid. 
     
     
       8. The process of claim 1, wherein said amine is selected from the group consisting of hydrazine, monoamines, substituted monoamines, diamines, substituted diamines, triamines, and substituted triamines. 
     
     
       9. The process of claim 1, wherein said amine is 2,4,6-tribromoaniline. 
     
     
       10. The process of claim 1, wherein said amine is hydrazine. 
     
     
       11. The process of claim 1, wherein said amine is monoethanolamine. 
     
     
       12. The process of claim 1, wherein said amine is melamine. 
     
     
       13. A process for the preparation of brominated phthalimides comprising the steps of: a. reacting tetrabromophthalic anhydride, organic acid, and an acidic dispersing agent in water to form a mixture;   b. heating said mixture to at least 110° C. under a first pressure;   c. adding an amine selected from a group comprised of hydrazine, monoamines, substituted monoamines, diamines, substituted diamines, triamines, and substituted triamines to said mixture to form a reactant mass having a molar ratio of anhydride/amine of 2:1;   d. heating said reactant mass to at least 120° C.; and   e. stirring said reactant mass under a second pressure for a period of time to yield said brominated phthalimide.   
     
     
       14. The process of claim 13, wherein said first pressure is approximately 1 bar pressure. 
     
     
       15. The process of claim 13, wherein said second pressure is approximately 5 bar pressure. 
     
     
       16. The process of claim 13, wherein said period of time is approximately 6 hours. 
     
     
       17. The process of claim 13, wherein said reactant mass is heated to approximately 150°-170° C. 
     
     
       18. The process of claim 13, wherein said water is about 80% by weight of said mixture. 
     
     
       19. The process of claim 13, wherein said acidic dispersing agent is selected from the group consisting of benzene, 1,1'-oxybis-, tetrapropylene derivatives, sulfonated, sodium salts; poly(oxy-1,2-ethanediyl),alpha-(nonylphenyl)-omega-hydroxy-, branched phosphates; and poly(oxy-1,2-ethanediyl),-alpha-(dinonylphenyl)-omega-hydroxy-, phosphates. 
     
     
       20. The process of claim 13, wherein said organic acid is selected from the group consisting of formic acid, acetic acid, and propionic acid. 
     
     
       21. The process of claim 13, wherein said amine is monoethanolamine. 
     
     
       22. The process of claim 13, wherein said amine is 2,4,6-tribromoaniline. 
     
     
       23. The process of claim 13, wherein said amine is hydrazine. 
     
     
       24. The process of claim 13, wherein said amine is melamine. 
     
     
       25. A process for the preparation of bis (tetrabromophthalimide) comprising the steps of: a. providing a reactor,   b. charging said reactor with 240 pounds of water, 2 pounds of organic acid, 2 pounds of acidic dispersing agent selected from the group consisting of benzene, 1,1'-oxybis-, tetrapropylene derivatives, sulfonated, sodium salts; poly(oxy-1,2-ethanediyl),alpha-(nonylphenyl)-omega-hydroxy-, branched phosphates; and poly(oxy-1,2-ethanediyl),-alpha-(dinonylphenyl)-omega-hydroxy-, phosphates, and 60 pounds of tetrabromophthalic anhydride to form a mixture;   c. healing while stirring said mixture to approximately 100° C. at approximately 1 bar pressure;   d. adding hydrazine to said mixture for approximately 30 minutes to form a reactant mass having a molar ratio of anhydride/amine of 2:1;   e. heating said reactant mass to 120°-170° C.;   f. stirring said reactant mass for approximately 6 to 15 hours;   g. cooling said reactant mass;   h. filter washing said reactant mass with hot water and then methanol; and   i. vacuum drying said reactant mass to form a very white powder bis (tetrabromophthalimide) product.   
     
     
       26. A process of claim 25, wherein said reactant mass is heated to approximately 150°-170° C. 
     
     
       27. A process of claim 25, wherein the reactant mass is stirred for approximately 6 hours. 
     
     
       28. A process of claim 25, wherein said product has a whiteness index of approximately 84.3 and a yellowness index of approximately 1.85. 
     
     
       29. A process of claim 25, wherein said product is approximately 97% bis-tetrabromophthalimide, 0.1% tetrabromophthalic anhydride, and 2.9% N-aminotetrabromophthalimide.